What do you mean by "personal statement"? I have given my involvement here, as well as other mathematics websites, as part of an appeal for an increase in pay. I also included my work maintaining trails in the local mountains. The president of my university was a trail runner and I claimed I was keeping him safe!
I got the raise though I have no idea whether those helped or not.
I mentioned how I like to watch the experts in the field (whether that's professors, grad students, w/e) go at it on certain topics (astrophysics, cosmology, beyond the standard model, QM, etc.) on forums on the internet. I never mentioned PF specifically though. But I can't remember if that was a personal statement for an internship or if I wrote that somewhere else ...
Be careful, you'd be surprised how many older people don't know what an internet forum is. They won't have any idea what you're talking about.